The present invention is directed to an optical device for frequency-selectively distributing light and in particular for demultiplexers in optical waveguide systems and to a process for producing the device.
Previously known frequency-selective optical light distributor devices have been constructed by means of either a blazed reflecting diffraction grating in conjunction with a gradient index lens, a CdS prism in association with two collimator lenses, a hologram, or a dichroic beam divider in the region of free beam propagation between collimator lenses. However, in particular, when used as a demultiplexer in optical waveguide systems, these types of light distributor elements necessitate a very high adjustment outlay and only possess poor selectivity. A high adjustment outlay is required, for example in the distributor element constructed with a CdS prism because of various reasons. These reasons include poor material dispersion, which requires following lenses to precisely focus the light onto the light inlet surfaces of the waveguide in the waveguide system, in particular, the end faces of the outgoing glass fibers or detector windows and that the position of the focal points arranged very close to one another would be determined by the dispersion angles. A poor selectivity is, for example, characteristic of the distributor element comprising a simple, obliquely adjusted dichroic beam divider in the region of free beam propagation.